Electrical generating system



Sept. 25, 1928.

F. F. STARR ELECTRICAL GNERA'IING SYSTEM Filed Jan. 30,y 1926 lIU Patented Sept. 25, 1928.

UNITED STATES PATENT OFFICE.

FRANK F. STARR, OF DAYTON, OHIO, ASSIGNOB T0 DELCO-LIGHT COMPANY, OF

` DAYTON, OHIO, A CORPORATION 0F DELAWARE.

ELECTRICAI GENERATING SYSTEM.

Application led January 30, 1926. Serial No. 84,803.

This invention relates to electrical generating systems and particularly to automatic systems which include an internal combustion engine, a storage battery, a work circuit and electrical apparatus operated by the storage battery for starting the engine andy operated by the engine for supplying current to the storage battery and to the work circuit. The engine is started automatically by a demand for current in the work circuit and is stopped automatically when the demand ceases.

One example of automatic system to which the present invention relates, is found in the copending application of Ernest Dickey, Serial No. 84,840 tiled January 30, 1926, which discloses a relay controlled by the closing of a switch in the work circuit for causing the engine to be cranked, and the ignition circuit of the engine to be rendered operative,- in order that the engine will run and the battery and work circuits will be supplied with current. The system also includes a device responsive to a certain relative large current demand in the work circuit for interrupting the How of current to the battery so that work circuit will receive the entire output of the apparatus.

One object of the present invention is to combine the two instruments referred to in a single structure in order to reduce the number of coils and magnetic circuits required in the system.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown. a

The Figure of the drawing is a wiring diagram illustrating the present invention.

In the drawing, 20 designates an internal combustion engine having a shaft 21 which drives a relatively high'voltage generator 22 havin main brushes 23 and 24 connected with t e armature of the generator, and having a series field winding 25 and a shunt field winding 26.

The engine is started by a relatively low Voltage series motor 27 which is normally disconnected from the engine, but may be connected automatically with the engine for cranking the latter whenever current is supplied to the motor; and which is automatically disconnected from the engine when the engine becomes self-operative. As various devices for automatically connecting and disconnecting the starting motor are wellknown to those skilled in the art, illustration ,thereof is deemed unnecessary. One form of mechanical connection which may be used with this invention isdescribed and claimed in the copending application of Frank F. Starr, Serial N o. 47,717, filed August 3, 1925.

The engine ignition apparatus comprises an ignition coil primary 30, an ignition timer 31 and. an ignition coil secondary 32 which 1s connected with an engine spark plug 33.

A relatively hi h-voltage work circuit which is supplied y the generator 22, includes wire 40, electrical translation devicesV 41 eaclicontrolled by a switch 42, wire 43, magnet coil 45, wire 46, switch contact 47, contact 48 and wire 49.

The battery charging circuit includes wire 50, reslstance 51, switch contact 52, contact 53, wire 54, a relatively low-voltage storage batter 55, wire 56, wire 57, switch contacts 58 an 59, contact 48 and wire 49.

The engine cranking circuit includes battery 55, wire 60, motor 27, wire 61, contact 62, contact 63 and wire 56. n

To start the engine automaticall spouse to a demand for current in t e work circuit, one of the switches 42 is closed, thereby causing current to How from the battery through the following circuit: battery 55, wlre 54, contact 53, contact 52, resistance 51, wire 50, wire 23, lield 25, wire 40, work device 41, switch 42, wire 43, magnet coil 45, magnet coil 64 and wire 56. Coil 64 is of relatively high resistance and, therefore, limits the current flowing from the battery to the work device 41. The energizlng of coils 45 and 64, which form part of a starting switch relay 65, causes an armature 66 to be drawn upwardly to connect amovable contact 67 with a stationary Contact 68. When contacts 67 and 68 are closed, current will flow from the battery through the magnet 69 of a starting switch 70 which includes a lunger 71 which, when moved upwardly, wil cause the contact 63, which is pivoted at 72l` to engage the contact 62. The circuit between the battery and the magnet 69 is" as follows: battery 55, wire 54, contacts 67 and 68, wire 168, wire 77, contacts 76 and l75, wire 74, magnet 69, wire 73, contact 79, contact 78, wire 178,V

in relun liu

and wire 56. The closing of contacts 62 and 63 will establish the cranking circuit previously described. TheV closing of contacts 67 and 68 will connect the ignition coil primary 30 with the storage battery through the following circuit: wire 54, contacts 67 and 68, wire 168, timer 31 ignition primary 30, wire 73, contacts 79 and 78, wire 178 and wire 56. Thus, the engine will be started by supplyin ignition thereto and cranking the engine y means of the starting motor 27.

If the engine should not start within a certain length of time, abnormal discharge of the batter is prevented by a cranking cut-out 81 which includes the contacts 78 and 79. The contact 79 is attached to a lever 82 which is pivoted at 83 and is urged upwardly by a spring 84. Upward movement of the lever 82 is restrained by the engagement of a non-conducting block 85 attached to the lever 82 with the lower end of a b1- metallic thermostat blade 86 fixed at 87 The blade 86. is in heat-receiving relation to a heating coil 88 which is connected across the battery terminals by connecting one end of the coil 88V with the Wire 60, and the other end with the wire 61. If the cranking of the engine should continue for an abnormal period, the bimetallic blade 86 will be heated sufiiciently to cause it to bow toward the left, as viewed in the drawing, until the lower end of the blade 86 moves past the shoulder 89 of the non-conducting block 85. When this occurs, the lever 82 will move upwardly and separate the contact 79 from the contact 78. This operation will disconnect the coil 69 from the battery 55, so that the plunger 71 will descend by gravity to move the contact 63 away from the contact 62. Thus, the starting circuit will be interrupted.

When the engine becomes self-operative and the generator has attained a, relatively high voltage, a load switch 90 will automatically connect the generator. with the work circuit referred to. The switch 90 includes a magnet coil 91 havin its ends connected, respectively, with t e generator brushes 23 and 24. When the voltage across the brushes exceeds a certain amount, the plunger 92 of the load switch will be attracted in order to move the contacts 48 and 47 into engagement. Before contact 48 engages contact 47, the contact 59 attached to contact 48 will first engage the contact 58.

This feature is provided to ensure the closing of the battery charging circuit before the work circuit is closed.

The engine cranking circuit is interrupted after the engine becomes self-operative, by a stop cranking relay 100 which includes the contacts 75 and 76, a magnet winding 101 connected across the brushes 23 and 24 of the nerator and a magnetizable plunger 102 aving lost-motion connection 103 with the contact 76 which is pivoted at 104. When the generator voltage reaches a certain relatively low value, the magnet coil 101 will be sufficiently energized to attract the plunger 102 in order to separate the contact 75 from the contact 76. When this occurs, the circuit between the battery and the magnet winding 69 of the starting switch 70 will be interrupted, thereby permitting the plunger 71 to descend and the contact 63 to be separated from the contact 62. After the plunger 102 has been moved lsufficiently by the magnet 101 to separate the contact 75 from the contact 7 6, the plunger 102 will be maintained in this position, although the speed of the engine and the corresponding voltage of the generator will fall materially below the speed and voltage producin the separation of the contacts 75 and 7 6. hus, the possibility of reconnectin the starting circuit after the engine is sel perative has been eliminated, although the engine speed might become comparatively low.

Magnet coils 64 and 45, contacts 67 and 68, and contacts 52 and 53 are included in an instrument which serves to effect the operation of the starting apparatus and to close the ignition circuit and to maintain it closed until the current demand in the work circuit ceases, and to interrupt the flow of current to the battery when the current demand in the work circuit exceeds a certain amount.

The instrument or relay 65 comprises a' magnetizable an le 165 attached to a core 166 located within the windings 45 and 64. The angle 165 supports the armature 66 by a flexible metallic hinge 168. The contact 67 is` carried b a flexible metallic conductor 167 attache to the armature 66. The contact 53 is carried by a flexible, magnetizable metallic member 153 connected with the angle 165 by a non-ma etizable block 154. When the current flowing through coil 45, which is in the work circuit, exceeds a certain amount the magnetic path provided by members 166, 165 and 66 will be saturated and some of the flux will stray into the region of the ma etizable member 153 to cause the same to drawn toward the angle 165 to separate contact 53 from contact 52. In this way the battery charging circuit is interrupted when the demand for current in the work circuit exceeds a certain amount.

From the foregoing description, it is apparent that the invention includes an instrument having the functions of closing and maintaining vclosed the engine ignition circuit while there is a demand for current in the work circuit, and of interrupting the battery charging circuit when the current demand in the work circuit exceeds a certain amount.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming Within the scope of the claims which follow.

What is claimed is as follows:

l. An electrical generating system comprising, in combination, an internal combustion engine, a generator driven thereby, a work circuit supplied by the generator, engine ignition apparatus, a storage battery, and a single electromagnetic device for maintaining the ignition apparatus operative While the generator supplies current to the Work circuit and for interrupting the flow of current from the generator to the battery when the current demand in the Work circuit exceeds a certain amount.

2. An electrical generating system comprising, in combination, an internal combustion engine, a generator, driven thereby, a Work circuit supplied by the generator, engine ignition apparatus, a storage battery, and an electro-magnetic device having a coil and parts providing a magnetic circuit which include a magnetizable armature for maintaining operative said engine ignition apparatus While the generator is supplying current to the work circuit, and having a magnetizable member which is attracted toward said magnetic circuit parts when said circuit is saturated to a certain extent, in order to interrupt the battery charging circuit when the current demand in the Work circuit exceeds a certain amount.

3. An electrical generating system comprising, in combination, a prime mover, a generator driven thereby. a work circuit supplied by the generator, and a single electromagnetic device, for maintaining said engine operative while the generator supplies current to the Work circuit and for interrupting the flow of current from the generator to the battery When the current demand in the work circuit exceeds a certain amount.

4. An electrical generating system comprising, in combination, a prime mover, a generator driven thereby, a Work circuit supplied by the generator, and a single electromagnetic device having an armature for maintaining said engine operative While the generator supplies current to the Work circuit and having a magnetizable member Wh'ich is actuated to interrupt the flow of current to the battery when the current demand in the Work circuit exceeds a certain amount. l

5. An electrical generating system comprising, in combination, a prime mover, a generator driven thereby, a Work circuit supplied by the generator, and a single electromagnetic device having a magnet Winding in series with the Work circuit for maintaining said engine operative While the generator supplies current to the work circuit and for interrupting the flow of current from the generator to the battery when the current demand in the work circuit exceeds a certain amount. v

In testimony whereof I hereto aiix my signature.

FRANK F. STARR. 

